WO2007093331A1

WO2007093331A1 - Screening fabric

Info

Publication number: WO2007093331A1
Application number: PCT/EP2007/001144
Authority: WO
Inventors: Walter Haver; Frank Meyer; Stefan Butenkemper
Original assignee: Haver & Boecker Ohg
Priority date: 2006-02-16
Filing date: 2007-02-10
Publication date: 2007-08-23
Also published as: EP1985166A1; EP1985166B1; DE102006007518A1

Abstract

Screening fabric having a wire fabric which is woven continuously from threads over an extensive fabric area, wherein the threads comprise warp threads and weft threads which extend transversely with respect to the former, and the warp and the weft threads are connected to one another via at least one weave type, wherein one part of the threads is composed at least partially of a non-metal, in order to increase the drapability of the wire fabric.

Description

Wearable weave

The present invention relates to a Abschirmgewebe which is suitable for large-scale use in or on fiber-reinforced components and devices to electromagnetic

Shield radiation. The invention further relates to a provided with a Abschirmgewebe wall or a component equipped therewith.

Shielding fabrics designed as wire mesh have been known in the art, wherein between two layers of a composite material a laminate with a wire mesh is introduced to effect a shielding of electromagnetic radiation. In this case, the laminate is first made of the wire mesh and several different layers before it is introduced for the production of the component between the two fiber-reinforced layers, which are then visible later from both sides of the finished component.

A shielding wall or a component produced in this way can also meet high requirements in terms of stability and the electrical shielding effect. For simple flat surfaces, it also satisfies the optical requirements of such components. The disadvantage, however, is that conventional wire mesh often adapts unsatisfactorily to the three-dimensional surface structure, especially on three-dimensionally curved surfaces and projections, since the drapability of the wire mesh is insufficient. Wrinkles can occur in the wire mesh, which often remain visible on the finished surface of the fiber composite later. That can do it state that such components are unsuitable for use in visible places in aircraft or vehicle construction.

It is therefore the object of the invention to provide a further Abschirmgewebe available, which allows a better drapability of the wire mesh. A further aspect is to provide a wall equipped with a shielding fabric, in which a drape of the wire mesh of the shielding fabric is reduced.

The object is achieved according to the invention by a shielding fabric having the features of claim 1 and by a wall having the features of claim 21. Preferred developments and refinements are the subject of the dependent claims.

The shielding fabric according to the invention has a wire mesh woven from yarn over an extensive fabric surface. The threads of the wire mesh include warp thread and weft yarn extending transversely thereto. The warp and weft threads are connected together by at least one type of binding. Part of the filaments is at least partially made of a non-metal to increase the drapability of the wire mesh.

The invention has many advantages. Surprisingly, it has been found that thread made of nonmetal metal thread between bring a considerable flexibility of the shielding tissue with it.

In this case, the non-metal preferably consists of a substance that can be easily connected to a base plate on which the wire mesh is to be attached later. The electromagnetic radiation is reliably protected by the metallic the shielded and derived by the wire mesh. The non-metallic threads considerably increase the deformability and the adaptability to three-dimensional shapes, so that a flexible and wrinkle-free production of shielding components is possible.

The increased drapability causes the application of the shielding fabric to curved surfaces is easier and at the same time the quality of the surface can be increased, since a drape is avoided in many cases, while on the other hand a sufficient shielding effect is achieved.

In a preferred development, the wire mesh has a type of weave which has an increased drapability compared to a plain weave. In particular, at least a flat portion of the wire mesh is provided with a type of binding that allows for increased drapability and / or deformability. This is very advantageous since a particularly high adaptation of the screening fabric to a curved surface is achieved.

In preferred developments, the type of binding is based on an atlas and / or a twill weave. In particular, an atlas bond and bonds derived therefrom lead to a significantly increased drapability compared to a fabric weave woven with a canvas weave with otherwise comparable fabric values.

Developments of the invention in which a wafer binding is used or in which a type of binding based on a wafer bond is used are particularly preferred. A waffle weave has a honeycomb-like relief and Due to the high floats of the thread, good drainability is required. The same applies to a pointed twill weave, which also has high floats and good drapability.

In preferred developments, at least part of the warp and weft threads at least partially made of a non-metal, in particular, some threads are completely or at least substantially entirely of a non-metal.

The threads of non-metal serve to fix the other thread and allow in the subsequent further processing a high bond between the base plate and wire mesh, which is also based on the penetration of the materials. In all cases, a non-metal can be used or several different non-metals can be used.

A significant disadvantage of the laminates used in the prior art is the high workload in the production and connection of the individual layers of the laminate and the wall or of the component. This is because the wire cloth layer and the other several different layers have to be manufactured separately and then joined together in an expensive manner. This requires a considerable manpower or machine and time.

With the shielding fabric according to the invention, however, the shielding fabric is produced directly in one step. It is possible directly after the weaving of the wire mesh further processing. A separate treatment and an additional connection step is not necessary. This offers quite considerable advantages over the prior art. The Applicant therefore points out that according to the invention also in average drapability of the wire mesh can be achieved significant advantages.

In all embodiments, it is preferred that at least some threads at least partially made of a plastic. In particular, at least some of the threads are completely or at least substantially entirely made of a plastic. Preferably, thermoplastic materials, such as polyester, polyethylene or polyamides are used. Such thermoplastic materials can be melted at high temperatures to provide a strong bond with the base sheets. Suitable temperatures hung on the used material and are, for example for polyamide at about 215 ⁰ C and for polyethylene at about 100-150 ⁰ C.

The non-metal filaments significantly increase the fixability of the crossing points. Plastic threads in particular make a significant contribution to stability.

In preferred embodiments, some filaments may also include a fiber reinforced core and a sheath of a thermoplastic material.

In principle, the wire mesh also always has metallic thread, since the shielding effect is ensured by the electrical conductivity of the metal thread. In preferred developments, some threads have a metallic core and a cladding of a non-metal.

Preferably, the warp thread and the weft thread are electrically connected. This is usually an essential point of a shielding fabric, as electromagnetic radiation speaking frequency is reliably prevented only if the distance of the contact points between the individual thread is not too large.

In principle, some threads can also consist of a metal core and a plastic sheath.

In preferred developments, threads of a non-metal are provided at periodic intervals. For example, In the warp and weft directions, every second or every third or every fourth or every fourth warp and / or weft thread can be made of plastic. Preferably, every other thread is made of a plastic. Also possible are periodic patterns. Thus, in a larger pattern, e.g. initially two plastic threads be provided, connect to the two metal thread u.s.w. In other embodiments, more complicated patterns may also be provided, e.g. first two plastic threads, then one of metal, then one of plastic and finally two of metal, whereupon the order is repeated.

In all embodiments, the wire mesh is particularly homogeneous in some areas.

Embodiments are also possible and preferred in which a plurality of regions or sections are each provided homogeneously. This can be realized, for example, over regions of different types of bonding over the area. One possible application is, for example, the specifically tailored production of shielding fabrics, in which the body to be shielded has a larger flat surface and subsequent stronger bulges. For the different flat segments, the fabric can then be made appropriately adapted. In order to avoid wrinkles, in curved areas, the weave type of the fabric can be adjusted by choosing a weave style that allows for greater drapability, while selecting a weave with less drapability on flat surfaces. A waffle weave or the like is preferably used in arched areas, while a flat weave is also possible for flat surfaces. As a result, a drape is reliably avoided.

In principle, the mesh size of the fabric, as well as the wire diameter of the metal thread and the non-metallic thread used depend on the application and can accordingly be different.

In individual embodiments, mesh sizes of up to 10 or 15 mm with wire diameters of up to 1 or 2 mm are possible.

In preferred refinements and developments, the typical diameter of the synthetic and / or natural thread used is less than 500 μm, in particular less than 250 μm, and preferably less than 150 μm.

The typical diameter of the metal thread used is in particular less than 500 μm, preferably less than 150 μm and particularly preferably less than 100 μm.

In preferred embodiments, the mesh size of the fabric is less than 500 μm, in particular less than 200 μm, and preferably less than or equal to 150 μm. In particularly preferred embodiments, the mesh size is about 150 microns and the diameter of the metal thread at about 30 to 50 microns. Preferably, the number of stitches per inch long is less than 200 and / or large 50.

All numerical values given above are to be regarded as guideline values, so that deviations upwards and downwards are possible, in particular by 20%.

In preferred embodiments and further developments, additional threads made of plastic may be provided, which are then arranged adjacent to metal thread in warp and / or weft direction. In particular, the additional thread are close to metal thread.

Preferably, at least some of the filaments or metallic filaments of the filament are at least partially made of a material taken from a group of materials including tin bronze, steel, stainless steel, brass, copper, titanium, gold, silver and aluminum, and the like. In particular, the use of metal alloys or metal mixtures is possible.

In preferred embodiments, at least some threads consist of a multifilament, which in particular comprises at least partially homogeneous wires, twine, metal fiber yarn, ropes and / or strands.

The invention is also directed to a wall or component comprising at least one fiber-reinforced outer layer comprising a shielding fabric as previously described. The use of the invention can be done on all possible devices. Preferred is the use of components of motor vehicles, such as on or in bonnets, doors, roofs, fenders. Likewise, the shielding fabric can be used on wind turbines as lightning protection. The use can also be made in aircraft, are provided in the fuselage components or the wings with a shielding fabric. In particular, the use of components made of fiber-reinforced plastics, in order to effect the function of the shielding there.

Further features, properties and advantages of the present invention will become apparent from the following description of the exemplary embodiments with reference to the accompanying drawings.

It shows:

Fig. 1 is a highly schematic plan view of a shield fabric with an atlas binding;

FIG. 2 is a highly schematic plan view of a shielding fabric with a twill weave; FIG. and

Fig. 3 is a highly schematic plan view of another Ab ^¬ screen fabric with a twill weave.

With reference to the attached FIG. 1, a first exemplary embodiment of a shielding fabric 1 according to the invention will now be described.

The shielding fabric 1 according to the invention, which is shown very schematically in FIG. 1, comprises warp threads 11 through 18 in warp direction and weft threads 21 through 28 transversely thereto. For the sake of brevity, only a few warp and weft wires are shown in the figures.

The type of weave of the wire mesh here is an Atlas 1/4 bond, i. H. here, that a weft thread 21 below the warp thread 13, then above four warp threads 14 to 17, then below the following warp thread 18 and then again o- more than four other warp thread (not shown) runs. So there is a regular pattern, which is repeated here after every five warp threads. Likewise, e.g. also an atlas-l / 3-binding possible, in which the pattern repeats after four threads. Other larger or smaller rapports are possible.

The course of the next weft thread 22 is offset by two warp threads, so that the weft thread 22 below the warp thread 11, then above the four following warp thread 12 to 15, again below the warp thread 16 and then again above the four following warp thread 17 etc. ,

The course of the third weft thread 23 is again offset by two warp threads, so that the weft thread 23 runs above the warp threads 11 to 13, below the warp thread 14 and again above the warp threads 15 to 18.

Accordingly, the fourth weft thread 24 runs below the warp threads 12 and 17 visible in FIG. 11 and above the warp thread 11, and 13 to 16 and 18 and the fifth weft thread 25 runs above the warp threads 11 to 14 and 16 to 18 and below the warp thread 15.

The sixth weft thread 26 has a course like the first weft thread 21, since in the case of the atlas 1/4 shown here. Tie the pattern after five warp or weft repeated. Likewise, the course of the weft thread 27 corresponds to that of the weft thread 22 and the course of the weft threads 28 and 23 also agree.

The satin weave, which is chosen here as the binding type, permits extensive drapability of the wire mesh 2, so that the wire mesh 2 can be well adapted to curved surfaces without creating a troublesome drape. Thus, a highly effective shielding fabric can be integrated into a curved surface made of a fiber composite material, wherein a visually appealing surface can be achieved.

The individual filaments of the wire mesh 2 here consist alternately of metal and of a thermoplastic material, such as e.g. Polyester or polyamide. Here, the warp threads 11, 13, 15 and 17 are made of metal and are shown unshaded in Fig.l, while the intermediate warp wires 12, 14 and 16, and the wire 18 made of plastic. The plastic threads are hatched in the illustration of FIG. 1, wherein the hatching is aligned in each case perpendicular to the longitudinal axis of the respective thread.

The weft threads 21, 23, 25 and 27 are also executed here in the exemplary embodiment as metal wires and hatched drawn here, wherein the hatching lines are aligned at 45 ° to the longitudinal direction of the respective thread. Also in the weft here change metal and plastic threads from each other, so that the weft thread 22, 24, 26 and 28 are designed as a plastic thread.

The alternating arrangement of metal thread and plastic thread increases the stability of the fabric and also leads to a significantly improved drapability of the fabric, while ensuring a sufficient shielding effect. The plastic threads cause additional fixation of the tissue.

The diameter 7 of the metal thread used here in the exemplary embodiment, depending on the application, approximately between 30 and 70 microns, typically 50 microns. The diameter 6 of the plastic thread used is typically between about 50 and 200 microns, typically about 80 to 150 microns. The mesh size 5 between the metal and plastic threads depends on the purpose of use and may be e.g. between 30 .mu.m and 150 .mu.m. The mesh between two metal filaments may be between 50 and 200 microns, typically about 140 or 150 microns. The exact mesh size depends on the required shielding effect and the frequency range to be shielded.

The metal threads are preferably made of tin bronze, if appropriate also of steel or stainless steel. It can also be used copper.

The inventive Abschirmgewebe 1 offers significant advantages over the prior art, since a faster and more cost-effective production of walls or components made of fiber composites is possible in which a wire mesh 2 is used to shield electromagnetic radiation.

The erfmdungsgemaße use of thread of a plastic material such as polyester or polyamide allows the production of highly drape-wearable wire mesh, which can be well adapted to curved surfaces or integrate into it. 2, a second exemplary embodiment of a Abschirmgewebes 1 is shown very schematically in a plan view. Again, there is only every other warp yarns 31, 33, 35 and 37 and every other weft thread 41, 43, 45 and 47 made of metal, while the interposed warp yarns 32, 34, 36 and 38, and the weft 42, 44 and 46 from consist of a thermoplastic material.

In contrast to the exemplary embodiment according to FIG. 1, the fabric 2 in the exemplary embodiment according to FIG. 2 has a twill weave as the type of weave. Also the twill weave allows a reasonable drapability of the wire mesh. In other embodiments, in particular, a waffle binding may be provided, which allows a particularly good drapability.

In the plan view of a wire cloth 2, which is shown very schematically in FIG. 3, the twill weave is again present as the type of weave, as is also the case with the wire cloth according to FIG. In contrast to the other exemplary embodiments, however, here only every third warp wire is made of a plastic, so that the warp wires 51 and 52, 54 and 55 and 57 and 58 are made of metal, while the warp threads 53 and 56 consist of a plastic. Here in the exemplary embodiment, every second weft wire 42, 44 and 46 made of plastic, while the weft wires 41, 43 and 45 are made of metal.

In other embodiments, it is preferred that plastic wires are provided only in warp or only in the weft direction.

In other preferred embodiments, some additional warp and / or weft threads made of plastic are provided in a regular wire mesh made of metal thread, which are then arranged between individual warp and / or weft threads made of metal. are net. For example, the additional plastic thread for fixing individual warp wires (or weft wires) can be used. Such additional thread (warp and / or weft thread) made of plastic can be tight against individual metal thread. Then, the distance between the metal filaments corresponds to the mesh size of the metal mesh, while the distance between the plastic filament and the adjacent metal filament may be close to zero or equal to zero.

In all embodiments, the plastic threads may not only be made of a thermoplastic material, but may include a core of carbon fiber or the like, around which a sheath of a thermoplastic material is provided.

The wall according to the invention or the component according to the invention comprises, in particular, a planar section of a fiber composite material in which a shielding fabric is integrated in order to prevent electromagnetic radiation.

Claims

Claims :

Shielding fabric (1) with a thread (11-18, 21-28) over an extensive fabric area continuously woven wire cloth (2), wherein the thread warp thread (11-18) and transversely extending weft thread (21-28) include and the warp yarns and the weft yarns are connected together by at least one type of weave, characterized in that a part of the yarns 12, 14, 16, 18, 22, 24, 26, 28) consists at least partly of a non-metal in order to increase the drapability of the wire mesh (2).

2. Shielding fabric (1) according to claim 1, characterized in that the wire mesh (2) has a type of binding which has a relation to a plain weave increased drapability.

3. Shielding fabric (1) according to claim 1 or 2, characterized in that the type of binding is based on an atlas weave (3) and / or twill weave (4).

4. Shielding fabric (1) according to claim 2 or 3, characterized in that the type of binding is based on a wafer bond.

5. Shielding fabric (1) according to at least one of the preceding claims, characterized in that a part of the warp thread and a part of the weft thread consists at least partially of a non-metal.

6. shielding fabric (1) according to at least one of the preceding claims, characterized in that some thread (12, 14, 16, 18, 22, 24, 26, 28) consist essentially completely of a non-metal.

7. shielding fabric (1) according to at least one of the preceding claims, characterized in that some thread (12, 14, 16, 18, 22, 24, 26, 28) at least partially made of a plastic.

8. shielding fabric (1) according to claim 7, characterized in that some threads have a fiber-reinforced core and a sheath made of a thermoplastic material.

9. shielding fabric (1) according to at least one of the preceding claims, characterized in that a part of the threads has a metallic core and a shell of a non-metal.

10. shielding fabric (1) according to at least one of the preceding claims, characterized in that threads are provided at a periodic intervals of a non-metal.

11. Shielding fabric (1) according to at least one of the preceding claims, characterized in that the warp thread

(11, 13, 15, 17) and the weft threads (21, 23, 25, 27) are electrically conductively connected.

12. shielding fabric (1) according to at least one of the preceding claims, characterized in that the wire mesh (2) is partially homogeneous.

13. shielding fabric (1) according to at least one of the preceding claims, characterized in that the diameter (6) of synthetic and / or natural thread (26) is less than 500 microns, in particular less than 250 microns, preferably less than 150 microns.

14. shielding fabric according to at least one of the preceding claims, characterized in that the diameter (7) of metal filaments (25) is less than 500 microns, especially less than 150 microns, preferably less than 100 microns.

15. Shielding fabric (1) according to at least one of the preceding

Claims, characterized in that a mesh size (5) is less than 500 microns and in particular less than 200 microns and preferably less than 150 microns.

16. shielding fabric (1) according to claim 14 and 15, characterized in that the mesh size (5) at about 150 microns and the diameter (7) of the metal thread (25) is about 50 microns.

17. Shielding fabric (1) according to at least one of the preceding claims, characterized in that a number of stitches per inch long is less than 200 and / or large 50.

18. shielding fabric (1) according to at least one of the preceding claims, characterized in that additional threads are provided of plastic, which are arranged adjacent to metal thread and in particular bear tightly against metal thread.

Shielding fabric according to at least one of the preceding claims, characterized in that at least some yarns consist at least partially of a material taken from a group of materials, tin bronze, steel, stainless steel, brass, copper, titanium, gold, silver and aluminum includes.

20. Shielding fabric according to the preceding claim, characterized in that at least some threads consist of a multifilament, which in particular comprises at least partially homogeneous wires, twisted yarn, metal fiber yarn, ropes and / or strands.

21 wall, comprising at least one fiber-reinforced outer layer and a Abschirmgewebe (1) according to at least one of the preceding claims.